<p>The relationship between sodium deficiency and consequent sodium appetite was examined in rats experiencing high endogenous levels of aldosterone prior to diuretic-induced sodium loss and in rats incapable of secreting aldosterone because of adrenalectomy. Sodium appetite of rats with high aldesterone secretion was characterized by marked over-compensation for sodium deficits while salt intake comparably deficient rats not experiencing high aldesterone secretion until after natriuresis was precisely sufficient to replace sodium loss. It is proposed that enhanced aldosterone secretion potentiates other natrorexigenic effects of sodium deficiency in the elicitation of sodium appetite, thereby resulting in salt intake in excess of need. Adrenalectomized rats also overcompensated for deficits incurred during sodium deprivation, but this is ascribed to repeated experience with sodium deficiency and replacement.</p>